textile design & innovations

Self Cleaning Technology: Nanosphere® from Schoeller Technologies

Mother nature was always the source of inspiration for new technologies. Many textile technologies have been adapted from similar nature processes or structures. On of the these adaption is the melt spinning to create filament yarns, copying the spinning process of silk from the silk worm.

In this article a different technology will be discussed, which is the self cleaning effect or the Lotus concept. The mechanise of self cleaning is not rare in nature. A spiky and hydrophobic waxy surface of a plant will allow the dirt to fall off the surface with the rain droplets. On example of these plant is the Lotus.

Fig (1): Lotus, Adapted from [3].

The surface of the Lotus leaf features a unique fine hierarchical structure consists of papillae with coating of agglomerated wax tubules, this structure is the basis for the superhydrophobicity of this plants [5].

On the left, the particles are redistributed by water in smooth surfaces. On the right the particles adhere ti the water droplet and remover from the surface on the self cleaning surface [4].

Fig (4): An example of particles adhere on the surface of mercury droplet to demonstrate the self cleaning effect. Picture adapted from [4].

In textiles, Nanoshpere® is a good example of applying this effect to create oil and water repellent surface. Nanoshpere® is the technology form Schoeller® that is used to transfer the self cleaning effect of the nature to the surface of the fabric by means of nano technology.

Fig (5): Nanoshpere® is the technology form Schoeller® transfers the self cleaning effects of certain plants to fabrics, picture courtesy of Nanoshpere® and Schoeller Technologies.

In the classical surface (left), there is a large contact area between the droplet or the particle and the fabric surface making the droplet or the particle adhere to the surface. But in the case of the Nanoshpere® (right) this contact area is reduced thus reducing the adherence significantly of droplets and particles to the surface of fabrics. For the Nanoshpere® surface, the water runs off and the dirts can be rinsed easily.

Fig (7): Examples of water droplets on the surface of the Nanoshpere® fabrics, picture courtesy of Nanoshpere® and Schoeller Technologies.

Fig (8): Examples of dirts on the surface of Nanoshpere® fabrics, picture courtesy of Nanoshpere® and Schoeller Technologies.

The video below summarises the NanoSphere® technology and how the fabric behave when being washed by water or when dirt fall on the surface.

The Nanoshpere® fabric can find a wide range of application, including functional fabric for out door activities and as protective garments.

Another application for this technology can be found in architecture, when the the surface of the concrete is kept clean from dirt and algae thus saving maintenance cost. To apply on concrete two methods can be used, either to use textile materials to give special pattern for the concrete during casting or by applying a technical textile on or under the concrete to carry the self cleaning function [2].

For more information about NanoSphere® technology and fabrics and other related technologies from Schoeller® you can see the links below: